Which genetic characteristic refers to mating unrelated animals to produce genetic variability?

The term that refers to mating unrelated animals to produce genetic variability is indeed outbred. Outbreeding typically involves crossing animals that are not closely related, which increases genetic diversity within the offspring. This genetic variability can lead to improved health, resilience, and adaptability in the population, as it introduces new alleles that might provide advantages in changing environments or breeding conditions.

In contrast, inbreeding refers to the mating of closely related individuals, which can lead to a decrease in genetic diversity and may increase the chances of genetic defects due to the expression of deleterious alleles. Co-isogenic and congenic strains relate to specific breeding strategies used in research to ensure uniformity in genetic backgrounds for experimental purposes, rather than promoting genetic variability.